Appraisal of: Horsley, T.; Dingwall, O.; Tetzlaff, J. M.; Sampson, M. Checking reference lists to find additional studies for systematic reviews. Cochrane Database Syst Rev. 2009;(1):MR000026.
The aim of this Cochrane review was to investigate the effectiveness of checking reference lists for the identification of additional, relevant studies for systematic reviews. From the 12 included studies, the authors found that there was some evidence to support the use of checking reference lists for locating additional studies in systematic reviews, although this evidence is mainly derived from heterogeneous studies of poor quality. They conclude that, in situations where the identification of all relevant studies through hand searching and Boolean database searching is difficult, it would seem prudent that authors of reviews check reference lists to supplement their searching.